In Vitro Maturation and Its Role in Clinical Assisted Reproductive Technology

A fresh start for IVM: capacitating the oocyte for development using pre-IVM

BACKGROUND

While oocyte IVM is practiced sporadically it has not achieved widespread clinical practice globally. However, recently there have been some seminal advances in our understanding of basic aspects of oocyte biology and ovulation from animal studies that have led to novel approaches to IVM. A significant recent advance in IVM technology is the use of biphasic IVM approaches. These involve the collection of immature oocytes from small antral follicles from minimally stimulated patients/animals (without hCG-priming) and an ∼24 h pre-culture of oocytes in an advanced culture system ('pre-IVM') prior to IVM, followed by routine IVF procedures. If safe and efficacious, this novel procedure may stand to make a significant impact on human ART practices.

OBJECTIVE AND RATIONALE

The objectives of this review are to examine the major scientific advances in ovarian biology with a unique focus on the development of pre-IVM methodologies, to provide an insight into biphasic IVM procedures, and to report on outcomes from animal and clinical human data, including safety data. The potential future impact of biphasic IVM on ART practice is discussed.

SEARCH METHODS

Peer review original and review articles were selected from PubMed and Web of Science searches for this narrative review. Searches were performed using the following keywords: oocyte IVM, pre-IVM, biphasic IVM, CAPA-IVM, hCG-triggered/primed IVM, natural cycle IVF/M, ex-vivo IVM, OTO-IVM, oocyte maturation, meiotic competence, oocyte developmental competence, oocyte capacitation, follicle size, cumulus cell (CC), granulosa cell, COC, gap-junction communication, trans-zonal process, cAMP and IVM, cGMP and IVM, CNP and IVM, EGF-like peptide and IVM, minimal stimulation ART, PCOS.

OUTCOMES

Minimizing gonadotrophin use means IVM oocytes will be collected from small antral (pre-dominant) follicles containing oocytes that are still developing. Standard IVM yields suboptimal clinical outcomes using such oocytes, whereas pre-IVM aims to continue the oocyte's development ex vivo, prior to IVM. Pre-IVM achieves this by eliciting profound cellular changes in the oocyte's CCs, which continue to meet the oocyte's developmental needs during the pre-IVM phase. The literature contains 25 years of animal research on various pre-IVM and biphasic IVM procedures, which serves as a large knowledge base for new approaches to human IVM. A pre-IVM procedure based on c-type natriuretic peptide (named 'capacitation-IVM' (CAPA-IVM)) has undergone pre-clinical human safety and efficacy trials and its adoption into clinical practice resulted in healthy live birth rates not different from conventional IVF.

WIDER IMPLICATIONS

Over many decades, improvements in clinical IVM have been gradual and incremental but there has likely been a turning of the tide in the past few years, with landmark discoveries in animal oocyte biology finally making their way into clinical practice leading to improved outcomes for patients. Demonstration of favorable clinical results with CAPA-IVM, as the first clinically tested biphasic IVM system, has led to renewed interest in IVM as an alternative, low-intervention, low-cost, safe, patient-friendly ART approach, and especially for patients with PCOS. The same new approach is being used as part of fertility preservation in patients with cancer and holds promise for social oocyte freezing.

Nuclear transfer improves the developmental potential of embryos derived from cytoplasmic deficient oocytes

Embryo development after fertilization is largely determined by the oocyte quality, which is in turn dependent on the competence of both the cytoplasm and nucleus. Here, to improve the efficiency of embryo development from developmentally incompetent oocytes, we performed spindle-chromosome complex transfer (ST) between in vitro matured (IVM) and in vivo matured (IVO) oocytes of the non-human primate rhesus monkey. We observed that the blastocyst rate of embryos derived from transferring the spindle-chromosome complex (SCC) of IVM oocytes into enucleated IVO oocytes was comparable with that of embryos derived from IVO oocytes. After transferring the reconstructed embryos into the uterus of surrogate mothers, two live rhesus monkeys were obtained, indicating that the nuclei of IVM oocytes support both the pre-and post-implantation embryo development of non-human primates.

The Late Effects of Cancer Treatment on Female Fertility and the Current Status of Fertility Preservation-A Narrative Review

Fertility counseling should be offered to all individuals of young reproductive age early in the patient's trajectory following a cancer diagnosis. Systemic cancer treatment and radiotherapy often have an inherent gonadotoxic effect with the potential to induce permanent infertility and premature ovarian failure. For the best chances to preserve a patient's fertility potential and to improve future quality of life, fertility preservation methods should be applied before cancer treatment initiation, thus multidisciplinary team-work and timely referral to reproductive medicine centers specialized in fertility preservation is recommended. We aim to review the current clinical possibilities for fertility preservation and summarize how infertility, as a late effect of gonadotoxic treatment, affects the growing population of young female cancer survivors.

Effectiveness, Flexibility and Safety of Switching IVF to IVM as a Rescue Strategy in Unexpected Poor Ovarian Response for PCOS Infertility Patients

BACKGROUND

According to the latest practice committee document, in vitro maturation (IVM) is a simple and safe procedure, especially in patients with polycystic ovary syndrome (PCOS). Does switching from in vitro fertilization (IVF) to IVM (IVF/M) help as a rescue infertility treatment for PCOS patients with an unexpected poor ovarian response (UPOR) tendency?

METHODS

This retrospective cohort study included 531 women with PCOS who had undergone 588 natural IVM cycles or had switched to IVF/M cycles from 2008 to 2017. Natural IVM was performed in 377 cycles, and switching IVF/M was performed in 211 cycles. The primary outcome measure was the cumulative live birth rates (cLBRs), and the secondary outcomes included laboratory and clinical outcomes, maternal safety, and obstetric and perinatal complications.

RESULTS

No significant difference was found in the cLBRs between the natural IVM and switching IVF/M groups (23.6% vs. 17.4%, p = 0.05). Meanwhile, the natural IVM group had a higher cumulative clinical pregnancy rate (36.0% vs. 26.0%, p = 0.01), and a decrease in the number of oocytes was obtained in the switching IVF/M group (13.5 vs. 12.0, p < 0.01). The number of good quality embryos in the natural IVM group was 2.2 ± 2.5, and 2.1 ± 2.3 (p = 0.64) in the switching IVF/M group. No statistically significant differences were observed in the number of 2 pronuclear (2PN) and available embryos. Ovarian hyperstimulation syndrome (OHSS) did not occur in the switching IVF/M and natural IVM groups, indicating a highly favorable outcome.

CONCLUSION

In PCOS infertile women with UPOR, timely switching IVF/M is a viable option that markedly reduces the canceled cycle, results in reasonable oocyte retrieval, and leads to live births.

Investigating and Modelling an Engineered Millifluidic In Vitro Oocyte Maturation System Reproducing the Physiological Ovary Environment in the Sheep Model

In conventional assisted reproductive technologies (ARTs), oocytes are in vitro cultured in static conditions. Instead, dynamic systems could better mimic the physiological in vivo environment. In this study, a millifluidic in vitro oocyte maturation (mIVM) system, in a transparent bioreactor integrated with 3D printed supports, was investigated and modeled thanks to computational fluid dynamic (CFD) and oxygen convection-reaction-diffusion (CRD) models. Cumulus-oocyte complexes (COCs) from slaughtered lambs were cultured for 24 h under static (controls) or dynamic IVM in absence (native) or presence of 3D-printed devices with different shapes and assembly modes, with/without alginate filling. Nuclear chromatin configuration, mitochondria distribution patterns, and activity of in vitro matured oocytes were assessed. The native dynamic mIVM significantly reduced the maturation rate compared to the static group (p < 0.001) and metaphase II (MII) oocytes showed impaired mitochondria distribution (p < 0.05) and activity (p < 0.001). When COCs were included in a combination of concave+ring support, particularly with alginate filling, oocyte maturation and mitochondria pattern were preserved, and bioenergetic/oxidative status was improved (p < 0.05) compared to controls. Results were supported by computational models demonstrating that, in mIVM in biocompatible inserts, COCs were protected from shear stresses while ensuring physiological oxygen diffusion replicating the one occurring in vivo from capillaries.

Optical coherence microscopy allows for quality assessment of immature mouse oocytes

In brief

Optical coherence microscopy is a label-free and non-invasive imaging technique capable of 3D subcellular structure visualization. Here we show that this method allows for quality assessment of immature mouse oocytes based on their chromatin conformation and can be a valuable addition to the toolkit used in assisted reproduction procedures.

Abstract

The success of assisted reproductive technologies, and particularly in vitro maturation, is tightly linked to the quality of oocytes. Therefore, there is a need for robust, reliable, and easy-to-assess biomarkers of oocyte developmental competence. Microscopy techniques visualizing oocyte intracellular structure could provide such biomarkers. However, fluorescence imaging methods, applied frequently in biology and allowing for detailed structural and dynamic studies of single cells, require fluorescent tags to visualize cellular architecture and may cause short- and long-term photo-damage. On the other hand, traditional light microscopy, although relatively non-invasive, does not provide detailed structural information. Optical coherence microscopy (OCM) is a promising alternative, as it does not require sample pre-processing or labelling and can provide 3D images of intracellular structures. Here we applied OCM to assess the chromatin conformation of immature mouse oocytes, a feature that corresponds with their transcriptional status and developmental competence and cannot be examined by traditional light microscopy. We showed that OCM distinguished oocytes with so-called non-surrounded nucleoli (NSN) and surrounded nucleoli (SN) chromatin conformation with very high sensitivity and specificity and that OCM scanning did not decrease the quality of oocytes. Finally, we cross-referenced OCM data with the oocyte ability to undergo normal nuclear and cytoplasmic maturation and proven that indeed oocytes scored with OCM as NSN mature less effectively than oocytes scored as SN. Our results suggest that OCM may be a valuable addition to the imaging toolkit used in assisted reproduction procedures.

Amphiregulin Supplementation During Pig Oocyte In Vitro Maturation Enhances Subsequent Development of Cloned Embryos by Promoting Cumulus Cell Proliferation

The oocyte in vitro maturation (IVM) technique is important in animal husbandry, biomedicine, and human-assisted reproduction. However, the developmental potential of in vitro matured oocytes is usually lower than that of in vivo matured (IVVM) oocytes. Amphiregulin (AREG) is an EGF-like growth factor that plays critical roles in the maturation and development of mammalian oocytes. This study investigated the effects of AREG supplementation during pig oocyte IVM on the subsequent development of cloned embryos. The addition of AREG to pig oocyte IVM medium improved the developmental competence of treated oocyte-derived cloned embryos by enhancing the expansion and proliferation of cumulus cells (CCs) during IVM. The positive effect of AREG on enhancing the quality of IVVM pig oocytes might be due to the activation of proliferation-related pathways in CCs by acting on the AREG receptor. The present study provides an AREG treatment-based method to improve the developmental competence of cloned pig embryos.

Single-cell quantitative proteomic analysis of human oocyte maturation revealed high heterogeneity in in vitro matured oocytes

Oocyte maturation is pertinent to the success of in vitro maturation (IVM), which is used to overcome female infertility, and produced over 5000 live births worldwide. However, the quality of human IVM oocytes has not been investigated at single-cell proteome level. Here, we quantified 2094 proteins in human oocytes during in vitro and in vivo maturation (IVO) by single-cell proteomic analysis and identified 176 differential proteins between IVO and germinal vesicle oocytes and 45 between IVM and IVO oocytes including maternal effect proteins, with potential contribution to the clinically observed decreased fertilization, implantation, and birth rates using human IVM oocytes. IVM and IVO oocytes showed separate clusters in principal component analysis, with higher inter-cell variability among IVM oocytes, and have little correlation between mRNA and protein changes during maturation. The patients with the most aberrantly expressed proteins in IVM oocytes had the lowest level of estradiol per mature follicle on trigger day. Our data provide a rich resource to evaluate effect of IVM on oocyte quality and study mechanism of oocyte maturation.

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Single-cell proteomic profiling of human oocytes matured in vitro and in vivo.

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Low correlation between protein and mRNA levels during human oocyte maturation.

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In vitro matured (IVM) oocytes exhibit higher heterogeneity at the proteome level.

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45 differentially expressed proteins between IVM and in vivo matured (IVO) oocytes.

History of fertility preservation

Background: Fertility preservation refers to a procedure performed to maintain the ability to become pregnant before receiving treatment with a risk of fertility loss, such as chemo- or radiation therapy. Examples of fertility-preserving procedures include freezing, sperm freezing, embryo freezing through in vitro fertilization, and ovarian tissue freezing.Current Concepts: Until the late 1990s, awareness of fertility preservation among clinicians and patients was relatively low, and the only way to preserve and restore fertility in women with cancer was the cryopreservation of embryos. However, as the survival rate of cancer patients increased and the treatment results of various diseases improved, interest in quality of life such as pregnancy and childbirth after treatment gradually increased, and became a driving force for the development of fertility preservation. In the 2000s, several centers began cryopreserving ovarian tissue, including primordial follicles from young patients before chemotherapy. Currently, ovarian tissue cryopreservation can be used in combination with in vitro maturation and egg vitrification techniques. Novel methods to improve follicle survival after transplantation are currently being investigated. Methods to improve follicle survival after transplantation and new ovarian protective agents to protect the ovaries from cytotoxic agents are currently being studied.Discussion and Conclusion: Advances in fertility-preserving technologies in the future will contribute to the delivery of healthy children by providing tailored treatments and more individualized fertility-preserving strategies to patients whose fertility is at risk.

NAT10 Maintains OGA mRNA Stability Through ac4C Modification in Regulating Oocyte Maturation

In vitro maturation (IVM) refers to the process of developing immature oocytes into the mature in vitro under the microenvironment analogous to follicle fluid. It is an important technique for patients with polycystic ovary syndrome and, especially, those young patients with the need of fertility preservation. However, as the mechanisms of oocyte maturation have not been fully understood yet, the cultivation efficiency of IVM is not satisfactory. It was confirmed in our previous study that oocyte maturation was impaired after N-acetyltransferase 10 (NAT10) knockdown (KD). In the present study, we further explored the transcriptome alteration of NAT10-depleted oocytes and found that O-GlcNAcase(OGA) was an important target gene for NAT10-mediated ac4C modification in oocyte maturation. NAT10 might regulate OGA stability and expression by suppressing its degradation. To find out whether the influence of NAT10-mediated ac4C on oocyte maturation was mediated by OGA, we further explored the role of OGA in IVM. After knocking down OGA of oocytes, oocyte maturation was inhibited. In addition, as oocytes matured, OGA expression increased and, conversely, O-linked N-acetylglucosamine (O-GlcNAc) level decreased. On the basis of NAT10 KD transcriptome and OGA KD transcriptome data, NAT10-mediated ac4C modification of OGA might play a role through G protein-coupled receptors, molecular transduction, nucleosome DNA binding, and other mechanisms in oocyte maturation. Rsph6a, Gm7788, Gm41780, Trpc7, Gm29036, and Gm47144 were potential downstream genes. In conclusion, NAT10 maintained the stability of OGA transcript by ac4C modification on it, thus positively regulating IVM. Moreover, our study revealed the regulation mechanisms of oocytes maturation and provided reference for improving IVM outcomes. At the same time, the interaction between mRNA ac4C modification and protein O-GlcNAc modification was found for the first time, which enriched the regulation network of oocyte maturation.

The Improvement and Clinical Application of Human Oocyte In Vitro Maturation (IVM)

Oocyte in vitro maturation (IVM) is a technology with a long history that was established before IVF. Although it has been studied extensively, the efficiency of IVM has been poor for almost 30 years. In terms of the benefits of IVM, the efficiency and adoption of IVM are being improved by some notable improvements that have occurred in recent years. The establishment of biphasic IVM is the most important advancement in recent years. Biphasic IVM includes the pre-IVM culturing phase and IVM phase. The CNP-mediated pre-IVM culturing system is specifically tailored for non/minimally stimulated immature oocytes, and its efficiency has been shown. This is the most significant improvement made in recent decades in this area. In the clinic, IVM can be used for PCOS patients to avoid the occurrence of ovarian hyperstimulation syndrome (OHSS). Additionally, this method can solve the reproductive problems of some patients with special diseases (resistant ovary syndrome) that cannot be solved by IVF. In most fertility preservation procedures, oocytes in small antral follicles are lost. However, IVM has the ability to capture this kind of oocyte and save reproductive potential. IVM can be easily combined with fertility preservation strategies that have been applied in the clinic and improve the efficiency of fertility preservation. IVM is a useful and attractive technology and may be used widely worldwide in the near future.

The impact of timing for estrogen supplementation in polycystic ovary syndrome patients undergoing primed in vitro maturation

OBJECTIVE

This study aims to determine the effects of early and late onset estrogen supplementation on the immature oocyte retrieval, fertilization and clinical pregnancy rates in follicle stimulating hormone (FSH) and human chorionic hormone (hCG) primed in vitro maturation (IVM) cycles of the patients with polycystic ovary syndrome (PCOS).

METHODS

This is a retrospective analysis of 161 patients with PCOS who underwent FSH and hCG primed IVM. Group 1 included 120 patients who received early onset estrogen supplementation while group 2 consisted of 41 patients who had late onset estrogen supplementation in primed IVM cycles. Immature oocyte (germinal vesicle and/or metaphase I) retrieval and fertilization rates were the primary outcomes, whereas clinical pregnancy and live rates were the secondary outcomes.

RESULTS

Group 1 patients had significantly higher body mass index and more previous IVF attempts (p = 0.001 and p = 0.008, respectively). All of the retrieved oocytes from the PCOS patients were either germinal vesicle or metaphase I oocytes and there were no metaphase II oocytes among the retrieved oocytes. Both groups had statistically similar numbers of metaphase I and fertilized oocytes (p > 0.05 for both). However, group 1 patients had significantly lower number of germinal vesicle oocytes but significantly higher number of metaphase II oocytes (p = 0.001 for both). Both groups had statistically similar fertilization (85.0% vs 78.0%), clinical pregnancy (49.2% vs 43.9%) and live birth (37.5% vs 39.0%) rates (p > 0.05 for all).

CONCLUSION

Early onset estrogen supplementation appears to improve the quality of retrieved immature oocytes and contribute to the maturation of oocytes in stimulated IVM cycles.

Maternal and neonatal outcome and children's development after medically assisted reproduction with in-vitro matured oocytes-a systematic review and meta-analysis

BACKGROUND

IVM was implemented in medically assisted reproduction 25 years ago. IVM does not involve controlled ovarian stimulation (COS) and is mainly indicated in patients with a high risk of ovarian hyperstimulation syndrome, in particular in patients with polycystic ovary syndrome (PCOS); it is also an acknowledged option in fertility protection. However, the in-vitro culture of immature oocytes raises concerns over their developmental potential and the putative impact on children's health. Although an increasing number of studies on obstetric and neonatal outcomes of IVM children and their development have been published in recent years, study designs are difficult to compare, since IVM is used in women with various indications and IVM protocols do not follow the same standards.

OBJECTIVE AND RATIONALE

The aim of this systematic review was to evaluate the current evidence from IVM children of an impact of in-vitro culture of immature oocytes. Primary outcome parameters were birthweight and children's development up to the age of 2 years. We also compared pregnancy pathologies and the outcome of IVM children and COS children in relation to maternal indications, in particular PCOS, and to the type of IVM protocols with or without ovulation trigger as the secondary outcome parameters. IVM is an accepted clinical option for many centres; however, a comprehensive analysis of the available data is needed to establish whether the use of human oocytes that are fully matured in vitro is safe for both children and their mothers.

SEARCH METHODS

Google Scholar and PubMed were used for identifying peer-reviewed original articles and reviews through January 2020. A total of 191 studies were screened and 16 studies were included in the qualitative synthesis. Studies were stratified according to indications, the use of an ovulation trigger and multiplicity.

OUTCOMES

Birthweights of IVM singletons and multiples were comparable to their respective COS controls: birthweights were also similar if the analysis was restricted to mothers with PCOS. IVM children had a comparable birthweight to COS children, irrespective of whether an ovulation trigger was used in IVM cycles or not. The frequency of gestational diabetes (GD) in singleton pregnancies was comparable between IVM and COS, regardless of infertility background. There was also no difference in GD frequency between IVM and COS, if an hCG ovulation trigger in IVM cycles was used or not. Hypertensive disorders in singleton pregnancies of women with PCOS were significantly more frequent after IVM compared to COS, in particular if IVM cycles were performed only with in-vitro matured oocytes. There was no difference in the preterm birth rate of singleton pregnancies between IVM and COS. Preterm birth rates were still similar if only women diagnosed with PCOS were compared and whether an ovulation trigger in IVM was used or not. The malformation rate in IVM children did not differ in COS children versus children after natural conception. At the age of 2 years, IVM singletons showed similar anthropometric and mental development compared to COS children or children from natural conception.

WIDER IMPLICATIONS

The higher incidence of hypertensive disorders in IVM pregnancies needs monitoring during pregnancy. Current data on the development of IVM children are encouraging, although the quality of many studies is limited and long-term data beyond 2 years are scarce. Further studies should be based on generally accepted IVM protocols. Studies on long-term outcomes beyond 2 years are needed to search for potential long-time sequelae of IVM.

In vitro maturation with letrozole priming: Can it be a solution for patients with cancerophobia? A pilot study

Objective:

To investigate whether letrozole priming could be used efficiently in patients undergoing in vitro maturation (IVM) as compared with follicle-stimulating hormone (FSH) priming.

Materials and Methods:

This is a retrospective analysis of 63 patients who underwent IVM due to the high risk of Ovarian Hyperstimulation syndrome (OHSS) (n=39), cancerophobia (n=16), and desire for IVM after failed in vitro fertilization attempts (n=8). Forty-two patients received FSH priming and 21 patients received letrozole priming.

Results:

The patients who had FSH or letrozole priming were statistically similar with respect to age, body mass index, duration of infertility, basal antral follicle count, serum anti-Müllerian hormone levels, and IVM indications (p>0.05 for all). When compared with the FSH priming group, the number of germinal vesicle oocytes, metaphase II and fertilized oocytes were significantly higher (p=0.003, p=0.001, and p=0.016, respectively), but the number of metaphase I oocytes was significantly lower in the letrozole priming group (p=0.002). The patients who received FSH and letrozole priming had statistically similar rates of implantation (33.3% vs 37.0%, p=0.709), clinical pregnancy (31.5% vs 33.3%, p=0.848), twinning (1.9% vs 3.7%, p=0.611), and live birth (24.1% vs 29.6%, p=0.682).

Conclusion:

Potential indications for IVM include patients with increased risk for OHSS and contraindication for hyperestrogenism. Aromatase inhibitors can be used to preserve the fertility of patients with estrogen-sensitive cancers. Letrozole priming appears to be an efficient approach in patients who undergo IVM, with likely less cost than FSH priming.

Senescence and Apoptosis During in vitro Embryo Development in a Bovine Model

According to the World Health Organization, infertility affects up to 14% of couples under reproductive age, leading to an exponential rise in the use of assisted reproduction as a route for conceiving a baby. In the same way, thousands of embryos are produced in cattle and other farm animals annually, leading to increased numbers of individuals born. All reproductive manipulations entail deviations of natural phenotypes and genotypes, with in vitro embryo technologies perhaps showing the biggest effects, although these alterations are still emerging. Most of these indications have been provided by animal models, in particular the bovine species, due to its similarities to human early embryo development. Oocytes and embryos are highly sensitive to environmental stress in vivo and in vitro. Thus, during in vitro culture, a number of stressful conditions affect embryonic quality and viability, inducing subfertility and/or long-term consequences that may reach the offspring. A high proportion of the embryos produced in vitro are arrested at a species-specific stage of development during the first cell divisions. These arrested embryos do not show signs of programmed cell death during early cleavage stages. Instead, defective in vitro produced embryos would enter a permanent cell cycle arrest compatible with cellular senescence, in which they show active metabolism and high reactive oxygen species levels. Later in development, mainly during the morula and blastocyst stages, apoptosis would mediate the elimination of certain cells, accomplishing both a physiological role in to balancing cell proliferation and death, and a pathological role preventing the transmission of damaged cells with an altered genome. The latter would acquire relevant importance in in vitro produced embryos that are submitted to stressful environmental stimuli. In this article, we review the mechanisms mediating apoptosis and senescence during early embryo development, with a focus on in vitro produced bovine embryos. Additionally, we shed light on the protective role of senescence and apoptosis to ensure that unhealthy cells and early embryos do not progress in development, avoiding long-term detrimental effects.

Effect of follicle-stimulating hormone on Bligon goat oocyte maturation and embryonic development post in vitro fertilization

Background and Aim

Bligon goat is a crossbreed between Etawah and Kacang goat. This crossbreed goat is mostly reared by small farmers. In vitro maturation allows female goat (does) contributes toward reproduction despite the fact that the animal has been slaughtered. The aim of this study was to determine the in vitro maturation rate of Bligon goat oocytes supplemented with follicle-stimulating hormone (FSH), and their ability for further embryonic development after in vitro fertilization.

Materials and Methods

Experiment was conducted at the Laboratory of Animal Physiology and Reproduction, Faculty of Animal Science, Universitas Gadjah Mada, Yogyakarta, using Bligon goat ovaries obtained from local slaughterhouse around Yogyakarta. One thousand five hundred cumulus-oocyte complexes were matured for 24 h in tissue culture medium 199 supplemented with 50 IU/L FSH or without FSH (control). First, matured oocytes were evaluated its morphology based on the expansion of cumulus cells and PB1 extrusion. Next, 600 oocytes were then stained with 1% aceto-orcein to examine maturation based on changes in the configuration of chromosomes and nuclear membrane breakdown. Oocytes were considered mature when they reached metaphase II. To prove the ability of mature oocytes to develop into embryos, 900 oocytes were processed for fertilization in vitro. The data were analyzed using analysis of variance.

Results

The results indicated that FSH supplementation significantly increased oocyte maturation rate (65.21±7.26 vs. 43.25±6.23%) as indicated by extrusion of PB1 and homologous chromosome pairing and lined in the equator. The rate of degeneration was lower in the FSH-supplemented medium (3.21±0.25 vs. 10.17±3.15%). The blastocyst stage of oocyte developed embryos was reached by 12.43±2.15% and 22.28±4.86% of the control and treatment groups, respectively.

Conclusion

FSH supplementation significantly improves oocyte maturation and yields mature oocytes for future embryo development in vitro.

Quercetin promotes in vitro maturation of oocytes from humans and aged mice

Maternal fertility declines irreversibly with aging, and advanced maternal age is mostly related to impaired oocyte quality. The flavonol compound quercetin is considered to be an anti-aging agent due to its cytoprotective actions as an antioxidant. However, its role and mechanisms on aged oocytes are unclear. In this study, the quercetin promotes in vitro maturation (IVM) and early embryonic development of oocytes from aged mice. It is extended these findings in human oocytes, showing that quercetin promotes the IVM rate by 19.6% and increases the blastocyst formation rate by 15.5% compared to untreated controls. The overall oocyte quality of aged mice is improved by quercetin treatment, assessed as spindle/chromosome morphology and cortical granule distribution. Mitochondria is the primary endogenous source of age-related oxidative stress, and an RNA-seq analysis of quercetin-treated oocytes reveals molecular insights including scavenged mitochondrial-ROS, reduced apoptosis, and improved autophagy. Further, this study demonstrates that quercetin reduces ROS via SIRT3-mediated acetylation of SOD2's K68 residue. Thus, beyond demonstrating that quercetin confers beneficial mitochondria-related impacts in aged oocytes, this study illustrates a potential strategy to prevent or delay oocyte aging and to improve success rates of assisted human reproductive technologies (ART).

Safe and successful use of oocyte in-vitro maturation in two infertile women with multiple sclerosis

There is evidence to support an impact of ovarian stimulation with gonadotrophin-releasing hormone analogues on the progression or recurrence of multiple sclerosis. In addition, there is no universally acknowledged approach toward ovarian stimulation in patients with multiple sclerosis. This report describes two patients at a large tertiary university hospital who underwent an in-vitro maturation protocol in order to avoid a risk of exacerbating their multiple sclerosis by ovarian stimulation. Both patients were referred to the infertility clinic because of the concern of exacerbation of multiple sclerosis during or after ovarian stimulation treatment. The patients underwent the in-vitro maturation protocol to avoid ovarian stimulating agents. Both patients gave birth to healthy babies at term. They did not suffer any relapses of multiple sclerosis during their treatment or during pregnancy. Exacerbation of disease related to ovarian stimulation encourages the search for a safer approach to these patients. To the authors' knowledge, these are the first babies described in the literature who were born after in-vitro maturation to mothers suffering from multiple sclerosis. In-vitro maturation can thus be recommended as an alternative in suitable women with multiple sclerosis.

[Desire for pregnancy and breast cancer]

Breast cancer affects about 3,000 new women of childbearing age each year. The desire for pregnancy is therefore a frequent issue in the management of breast cancer. We reviewed the current state of knowledge and recommendations in high-risk women, on the consideration of this desire for pregnancy in therapeutic management, the way to approach it, the preservation of fertility in the care process and finally on the outcomes of pregnancy after breast cancer. We evaluated the desire for pregnancy, qualitatively and quantitatively, after breast cancer through a literature review.

Human Chorionic Gonadotropin Priming Does Not Improve Pregnancy Outcomes of PCOS-IVM Cycles

Background: Influence of pre-retrieval human chorionic gonadotropin (HCG) priming on outcomes of in vitro maturation (IVM) remains controversial. This study aimed to evaluate the effect of HCG priming before oocyte retrieval on clinical outcomes of IVM cycles in patients with polycystic ovarian syndrome (PCOS). Methods: This was a retrospective cohort study analyzing data from the first IVM cycles of unstimulated PCOS patients in a reproductive center of university affiliated hospital from January 2006 to December 2017. Patients received HCG injection before oocyte retrieval were assigned to HCG priming group and those without HCG administration were categorized as none HCG priming (Non-HCG) group. Main outcomes included oocyte maturation rate, number of embryos available, clinical pregnancy rate, and live birth rate. Candidate factors of clinical pregnancy rate was explored by univariate analysis and multivariate logistic regression analysis. Results: There were 324 patients meeting the inclusion and exclusion criteria. Among them, 129 women received HCG priming and 195 other did not. Women in HCG group had significantly lower basal FSH level (5.17 ± 1.63 vs. 5.80 ± 2.38) than Non-HCG group. Both FSH levels were <10 IU/L and the absolute difference was 0.63 IU/L. Other basic characteristics were similar between groups with or without HCG priming. Oocyte maturation rate was trend to be higher in HCG group (52.68 vs. 48.56%) but no statistical significance was found (P = 0.097). No significant difference in clinical pregnancy rate was found between HCG and Non-HCG groups (31.37 vs. 35.67%). Miscarriage rates (31.25 vs. 34.43%) and live birth rates were also similar between groups. HCG priming was not correlated with clinical pregnancy rate in both univariate analysis (P = 0.468) and multivariate logistic regression analysis (P = 0.538; OR = 1.212; 95%CI: 0.657-2.237). Conclusion: HCG priming before oocyte retrieval may not improve clinical outcomes of IVM in patients with PCOS.

Obstetric and neonatal outcome of ART in patients with polycystic ovary syndrome: IVM of oocytes versus controlled ovarian stimulation

STUDY QUESTION

Does IVM of immature oocytes retrieved from small antral follicles in women with polycystic ovary syndrome (PCOS) have an impact on obstetric and neonatal outcomes compared to controlled ovarian stimulation (COS)?

SUMMARY ANSWER

Obstetric and neonatal outcomes after IVM appear to be similar to those after COS.

WHAT IS KNOW ALREADY

Women with PCOS have an increased risk of adverse pregnancy outcomes and congenital malformations in their offspring. For patients with PCOS who require IVF, IVM of germinal vesicle (GV)-stage oocytes retrieved from antral follicles has been adopted as a mild approach ART, with improved pregnancy rates over the last two decades. Although reports of obstetrical and neonatal outcomes after IVM have been reassuring, the limited sample sizes in previous studies preclude firm conclusions, and further study is warranted.

STUDY DESIGN, SIZE, DURATION

This is a retrospective observational study analysing obstetric and neonatal data from 1036 clinical pregnancies in unique patients with PCOS who conceived following a cycle of IVM or COS between January 2010 and December 2016 in a tertiary reproductive centre. In total, 393 singleton pregnancies with a gestational age beyond 20 weeks were included. A phenotypic approach was used for the diagnosis of PCOS. Pregnancies following oocyte donation, standard IVF (as opposed to ICSI) or preimplantation genetic testing and pregnancies requiring testicular biopsy in the male partners were excluded.

PARTICIPANTS/MATERIALS,SETTING, METHODS

Pregnancy outcomes were analysed in women with PCOS phenotype A, C or D, as defined by different combinations of the Rotterdam criteria. Data from 164 pregnancies beyond 20 weeks after IVM were compared with those from 229 pregnancies after COS. Pregnancies in the IVM group were obtained after minimal ovarian stimulation and IVF with ICSI of transvaginally collected GV oocytes that had reached the metaphase II stage in vitro after 28 to 40 h of culture. No hCG trigger was administered before oocyte retrieval. Outcome measures were analysed or reported in singleton pregnancies only and included adverse obstetric events and neonatal health parameters, in particular birthweight, prematurity, small-for-gestational age, large-for-gestational age, perinatal death and major/minor malformation rates. The incidence of hypertensive disorders of pregnancy (HDP) and birthweight was analysed by multiple linear and logistic regression, adjusted for relevant treatment variables and maternal characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

The IVM and the COS groups differed significantly (P < 0.001) for maternal circulating AMH levels and PCOS phenotype distribution, with more of the PCOS phenotype A in the IVM group. Pregnant women in the IVM group were younger than pregnant women in the COS group (P = 0.05). With regard to obstetric complications in singleton pregnancies, in the unadjusted analysis, mothers of infants in the IVM group more often had HDP (29/164 (17.9%) vs 22/229 (9.6%), P = 0.02) compared with mothers in the COS group. Singletons born after IVM and COS had a similar birthweight standard deviation score (SDS) (0.51 ± 0.94 after IVM vs 0.33 ± 1.05 after COS, P = 0.19). Preterm birth rate (32–36.9 weeks) and early preterm birth rate (<32 weeks) were also similar in both groups. The total malformation rate was 4.1% in singletons after IVM and 2.4% in singletons after COS. Multivariate linear regression analysis accounting for relevant confounders demonstrated that parity was the only independent predictive factor (P = 0.04) for birthweight SDS. Multivariate logistic regression analysis showed that BMI, parity and type of ART (IVM as opposed to COS) were significantly correlated with the incidence of HDP. Only patients with the PCOS phenotype A showed a tendency towards a higher risk of HDP in those who underwent IVM compared to those who had COS.

LIMITATIONS, REASONS FOR CAUTION

The study is limited by its retrospective nature and loss to follow-up of a subset of children with no information regarding congenital malformations. Furthermore, the paediatricians who assessed the children after birth were not blinded for the type of ART procedure.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides further evidence that, compared to COS, IVM of oocytes derived from small antral follicles does not adversely affect the neonatal health of the offspring of patients with PCOS. The observed increased risk of HDP in patients with PCOS phenotype A following IVM treatment warrants further scrutiny.

STUDY FUNDING/COMPETING INTEREST(S)

Translational IVM research at Universitair Ziekenhuis Brussel (UZ Brussel) and Vrije Universiteit Brussel (VUB) has been supported by grants from the Institute for the Promotion of Innovation by Science and Technology in Flanders (Agentschap voor Innovatie door Wetenschap en Technologie—IWT, project 110680), the Fund for Research Flanders (Fonds Wetenschappelijk Onderzoek–Vlaanderen—FWO, project G.0343.13) and the Belgian Foundation Against Cancer (HOPE project, Dossier C69). Clinical IVM research was supported by research grants from Cook Medical and Besins Healthcare. M.D.V. reports honoraria for lectures from Cook Medical and Besins Healthcare outside the submitted work. S.S.R. reports honoraria for lectures by MSD and Besins and research grants by MSD, Ferring and Merck Serono outside of the submitted work. C.B. reports personal fees from Merck-Serono, Ferring, IBSA, Finox, MSD and Abbott outside the submitted work. H.T. reports grants from Merck, MSD, Goodlife, Cook, Roche, Besins, Ferring, Mithra (now Allergan) and the Research Fund of Flanders (FWO) and consultancy fees from Finox, Abbott, Obseva and Ovascience outside the submitted work. The other authors have nothing to disclose.

Transcriptional status of mouse oocytes corresponds with their ability to generate Ca2+ release

In fully grown ovarian follicles both transcriptionally active (NSN) and inactive (SN) oocytes are present. NSN oocytes have been shown to display lower developmental potential. It is possible that oocytes that have not completed transcription before meiosis resumption accumulate less RNA and proteins required for their further development, including those responsible for regulation of Ca2+ homeostasis. Oscillations of the cytoplasmic concentration of free Ca2+ ions ([Ca2+]i) are triggered in oocytes by a fertilizing spermatozoon and are crucial for inducing and regulating further embryonic development. We showed that NSN-derived oocytes express less inositol 1,4,5-triphosphate receptor type 1 (IP3R1), store less Ca2+ ions and generate weaker spontaneous [Ca2+]i oscillations during maturation than SN oocytes. Consequently, NSN oocytes display aberrant [Ca2+]i oscillations at fertilization. We speculate that this defective regulation of Ca2+ homeostasis might be one of the factors responsible for the lower developmental potential of NSN oocytes.

Differential gene expression between in vivo and in vitro maturation: a comparative study with bovine oocytes derived from the same donor pool

Objective:

In vitro maturation has been shown to influence gene expression in oocytes, but a common shortcoming in reports on the matter has been the use of different donors in each experimental group thus disregarding donor effects. This study aimed to investigate the abundance of mRNA in oocytes matured in vivo and in vitro obtained from the same group of donors.

Methods:

A bovine model was used to assess the relative abundance of specific transcripts in in vitro-matured (IN VITRO-OPU) and in vivo-matured (IN VIVO-OPU) oocytes collected from the same donors by transvaginal ovum pick-up (OPU). Transcript abundance in oocytes from the IN VIVO-OPU group and oocytes matured in vitro but retrieved from different cows slaughtered at a commercial abattoir (IN VITRO-Abattoir group) was also compared. Total RNA was extracted from denuded oocytes and cDNA was produced via reverse transcription using an oligo(dT) primer for relative quantification of eight target transcripts by real-time PCR.

Results:

Oocytes in the IN VITRO-OPU group had lower (p<0.05) abundance of peroxiredoxin 1 (Prdx1), heat shock protein 70.1 (Hsp70.1), growth and differentiation factor 9 (Gdf9), and maternal antigen that embryo requires (Mater) transcripts than the oocytes in the IN VIVO-OPU group, all obtained from the same pool of donor cows. Similar results were seen in the comparisons involving the IN VIVO-OPU and IN VITRO-Abattoir groups (p<0.05).

Conclusion:

In vitro maturation affected the abundance of polyadenylated transcripts in the oocyte cytoplasm when compared to in vivo maturation induced by exogenous hormones in oocytes collected from the same donor pool.

Evidence summaries and recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome: assessment and treatment of infertility

STUDY QUESTION

What is the recommended assessment and management of infertile women with polycystic ovary syndrome (PCOS), based on the best available evidence, clinical expertize and consumer preference?

SUMMARY ANSWER

International evidence-based guidelines, including 44 recommendations and practice points, addressed prioritized questions to promote consistent, evidence-based care and improve the experience and health outcomes of infertile women with PCOS.

WHAT IS KNOWN ALREADY

Previous guidelines on PCOS lacked rigorous evidence-based processes, failed to engage consumer and multidisciplinary perspectives or were outdated. The assessment and management of infertile women with PCOS are inconsistent. The needs of women with PCOS are not being adequately met and evidence practice gaps persist.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Governance included a six continent international advisory and a project board, a multidisciplinary international guideline development group (GDG), consumer and translation committees. Extensive health professional and consumer engagement informed the guideline scope and priorities. The engaged international society-nominated panel included endocrinology, gynaecology, reproductive endocrinology, obstetrics, public health and other experts, alongside consumers, project management, evidence synthesis and translation experts. Thirty-seven societies and organizations covering 71 countries engaged in the process. Extensive online communication and two face-to-face meetings over 15 months addressed 19 prioritized clinical questions involving nine evidence-based reviews and 10 narrative reviews. Evidence-based recommendations (EBRs) were formulated prior to consensus voting within the guideline panel.

STUDY DESIGN, SIZE, DURATION

International evidence-based guideline development engaged professional societies and consumer organizations with multidisciplinary experts and women with PCOS directly involved at all stages. A (AGREE) II-compliant processes were followed, with extensive evidence synthesis. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was applied across evidence quality, desirable and undesirable consequences, feasibility, acceptability, cost, implementation and ultimately recommendation strength. The guideline was peer-reviewed by special interest groups across our partner and collaborating societies and consumer organizations, was independently assessed against AGREE II criteria and underwent methodological review. This guideline was approved by all members of the GDG and has been approved by the NHMRC.

MAIN RESULTS AND THE ROLE OF CHANCE

The quality of evidence (QOE) for the EBRs in the assessment and management of infertility in PCOS included very low (n = 1), low (n = 9) and moderate (n = 4) quality with no EBRs based on high-quality evidence. The guideline provides 14 EBRs, 10 clinical consensus recommendations (CCRs) and 20 clinical practice points on the assessment and management of infertility in PCOS. Key changes in this guideline include emphasizing evidence-based fertility therapy, including cheaper and safer fertility management.

LIMITATIONS, REASONS FOR CAUTION

Overall evidence is generally of low to moderate quality, requiring significantly greater research in this neglected, yet common condition. Regional health systems vary and a process for adaptation of this guideline is provided.

WIDER IMPLICATIONS OF THE FINDINGS

The international guideline for the assessment and management of infertility in PCOS provides clinicians with clear advice on best practice based on the best available evidence, expert multidisciplinary input and consumer preferences. Research recommendations have been generated and a comprehensive multifaceted dissemination and translation program supports the guideline with an integrated evaluation program.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was primarily funded by the Australian National Health and Medical Research Council of Australia (NHMRC) supported by a partnership with ESHRE and the American Society for Reproductive Medicine (ASRM). GDG members did not receive payment. Travel expenses were covered by the sponsoring organizations. Disclosures of conflicts of interest were declared at the outset and updated throughout the guideline process, aligned with NHMRC guideline processes. Dr Costello has declared shares in Virtus Health and past sponsorship from Merck Serono for conference presentations. Prof. Norman has declared a minor shareholder interest in the IVF unit Fertility SA, travel support from Merck and grants from Ferring. Prof. Norman also has scientific advisory board duties for Ferring. The remaining authors have no conflicts of interest to declare.

This article was not externally peer-reviewed by Human Reproduction Open.

In vitro maturation in subfertile women with polycystic ovarian syndrome undergoing assisted reproduction

BACKGROUND

Polycystic ovarian syndrome (PCOS) occurs in 4% to 7% of all women of reproductive age and 50% of women presenting with subfertility. Subfertility affects 15% to 20% of couples trying to conceive. A significant proportion of these women ultimately need assisted reproductive technology (ART). In vitro fertilisation (IVF) is one of the assisted reproduction techniques employed to raise the chances of achieving a pregnancy. For the standard IVF technique, stimulating follicle development and growth before oocyte retrieval is essential, for which a large number of different methods combining gonadotrophins with a gonadotrophin-releasing hormone (GnRH) agonist or antagonist are used. In women with PCOS, the supra-physiological doses of gonadotrophins used for controlled ovarian hyperstimulation (COH) often result in an exaggerated ovarian response, characterised by the development of a large cohort of follicles of uneven quality, retrieval of immature oocytes, and increased risk of ovarian hyperstimulation syndrome (OHSS). A potentially effective intervention for women with PCOS-related subfertility involves earlier retrieval of immature oocytes at the germinal-vesicle stage followed by in vitro maturation (IVM). So far, the only data available have derived from observational studies and non-randomised clinical trials.

OBJECTIVES

To assess the effectiveness and safety of IVM followed by IVF or ICSI versus conventional IVF or ICSI among women with PCOS undergoing assisted reproduction.

SEARCH METHODS

This is the second update of this review. We performed the search on 17 April 2018.The search was designed with the help of the Cochrane Gynaecology and Fertility Group Information Specialist, for all published and unpublished randomised controlled trials (RCTs).We searched the the Cochrane Gynaecology and Fertility Group Specialised Register of controlled trials, CENTRAL via the Cochrane Central Register of Studies Online, MEDLINE, Embase, CINAHL, and the trial registers for ongoing and registered trials and the Open Grey database for grey literature from Europe. We made further searches in the National Institute for Health and Care Excellence (NICE) fertility assessment and treatment guidelines. We handsearched reference lists of relevant systematic reviews and RCTs, together with PubMed and Google for any recent trials that have not yet been indexed in the major databases.

SELECTION CRITERIA

All RCTs on the intention to perform IVM before IVF or ICSI compared with conventional IVF or ICSI for subfertile women with PCOS, irrespective of language and country of origin.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias, extracted data from studies, and attempted to contact the authors of studies for which data were missing. Our primary outcomes were live birth per woman randomised and miscarriage. We performed statistical analysis using Review Manager 5. We assessed evidence quality using GRADE methods.

MAIN RESULTS

We found two RCTs suitable for inclusion in the review and six ongoing trials that have not yet reported results. Both included studies were published as abstracts in international conferences.Both studies were at unclear or high risk of bias for most of the seven domains assessed. Common problems were unclear reporting of study methods and lack of blinding. The main limitations in the overall quality of the evidence were high risk of bias and serious imprecision.There were no data on the primary outcomes of this review, namely live birth per woman randomised and miscarriage.Both studies reported clinical pregnancy rate: there was evidence of an effect between IVM and IVF, favouring the former (odds ratio 3.10, 95% confidence interval 1.06 to 9.00; 71 participants; 2 studies; I² = 0%; very low-quality evidence). The incidence of OHSS was zero in both studies in both groups.There were no data for the other outcomes specified in this review.

AUTHORS' CONCLUSIONS

Though promising data on the in vitro maturation (IVM) technique have been published, unfortunately there is still no evidence from properly conducted randomised controlled trials upon which to base any practice recommendations regarding IVM before in vitro fertilisation (IVF) or intracytoplasmic sperm injection for women with polycystic ovarian syndrome. Regarding our secondary outcomes, very low-quality evidence showed that clinical pregnancy was higher with IVM when compared to IVF, whereas the incidence of ovarian hyperstimulation syndrome was zero in both studies in both groups. We are awaiting the results of six ongoing trials and eagerly anticipate further evidence from good-quality trials in the field.

Oocyte in vitro maturation: A sytematic review

In vitro maturation (IVM) is one of the most controversial aspects of assisted reproductive technology. Although it has been studied extensively, it is still not a conventional treatment option and is accepted as an alternative treatment. However, studies have shown that IVM can be used in almost all areas where in vitro fertilization (IVF) is used and it has a strong place in fertility protection and Ovarian Hyperstimulation syndrome management. The aim of this systematic review was to address all aspects of the current knowledge of IVM treatment together with the evolution of IVM and IVF.

Treatment strategies for women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women, and it is the main cause of infertility in women of reproductive age due to anovulation. PCOS also increases the risk of diseases such as cardiovascular disease and type 2 diabetes in women with this disorder. The mechanism of pathogenesis is not clear, as it may be related to heredity, the environment and internal embryonic factors; thus, the treatment strategies remain unclear. This review summarizes current treatments for PCOS worldwide. Lifestyle modification (LSM) is considered the first-line treatment, regardless of fertility status, without the addition of metformin. Oral contraceptive (OC) pills should be used as a first-line treatment for long-term management for patients with no reproductive requirements. For patients with fertility requirements, ovulation therapy is an effective treatment. For refractory ovulation disorders, patients can choose from among the latest treatments, including ovarian hippocampal signal path block theory, the theory of leptin, inositol treatment, bilateral ovarian drilling to stimulate ovulation and assisted reproductive technology. Because current treatments cannot cure PCOS, lifelong administration is still the mainstream method of management; however, the optimal treatment plan needs further research and exploration.

Development of in vitro maturation techniques for clinical applications

In vitro maturation (IVM) refers to maturation in culture of immature oocytes at different stages that may or may not have been exposed to short courses of gonadotropins. The source of immature oocytes is an important feature for subsequent embryonic development, pregnancy, and healthy live births. IVM is an effective treatment that has already achieved significant outcomes of acceptable pregnancy and implantation rates and has led to the births of several thousand healthy babies. As the development of IVM treatment continues, an attractive possibility for improving the already successful outcome is to combine a natural-cycle in vitro fertilization (IVF) treatment with immature-oocyte retrieval followed by IVM of those immature oocytes. If the treatment processes can be simplified for immature-oocyte retrieval, different types of infertile women may be able to take advantage of these treatments. Mild-stimulation IVF combined with IVM treatment may represent a viable alternative to the standard treatment. Although IVM treatment is still considered to be experimental, it is now time to reconsider the IVM technology and its development. Mild-stimulation IVF combined with IVM may prove to be not just alternatives to standard treatments, but potentially first-line treatment choices.

Genetic and epigenetic risks of assisted reproduction

Assisted reproductive technology (ART) is used primarily for infertility treatments to achieve pregnancy and involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and cryopreservation. Moreover, preimplantation genetic diagnosis (PGD) of ART is used in couples for genetic reasons. In ART treatments, gametes and zygotes are exposed to a series of non-physiological processes and culture media. Although the majority of children born with this treatment are healthy, some concerns remain regarding the safety of this technology. Animal studies and follow-up studies of ART-borne children suggested that ART was associated with an increased incidence of genetic, physical, or developmental abnormalities, although there are also observations that contradict these findings. As IVF, ICSI, frozen-thawed embryo transfer, and PGD manipulate gametes and embryo at a time that is important for reprogramming, they may affect epigenetic stability, leading to gamete/embryo origins of adult diseases. In fact, ART offspring have been reported to have an increased risk of gamete/embryo origins of adult diseases, such as early-onset diabetes, cardiovascular disease, and so on. In this review, we will discuss evidence related to genetic, especially epigenetic, risks of assisted reproduction.

Optical coherence microscopy as a novel, non-invasive method for the 4D live imaging of early mammalian embryos

Imaging of living cells based on traditional fluorescence and confocal laser scanning microscopy has delivered an enormous amount of information critical for understanding biological processes in single cells. However, the requirement for a high numerical aperture and fluorescent markers still limits researchers’ ability to visualize the cellular architecture without causing short- and long-term photodamage. Optical coherence microscopy (OCM) is a promising alternative that circumvents the technical limitations of fluorescence imaging techniques and provides unique access to fundamental aspects of early embryonic development, without the requirement for sample pre-processing or labeling. In the present paper, we utilized the internal motion of cytoplasm, as well as custom scanning and signal processing protocols, to effectively reduce the speckle noise typical for standard OCM and enable high-resolution intracellular time-lapse imaging. To test our imaging system we used mouse and pig oocytes and embryos and visualized them through fertilization and the first embryonic division, as well as at selected stages of oogenesis and preimplantation development. Because all morphological and morphokinetic properties recorded by OCM are believed to be biomarkers of oocyte/embryo quality, OCM may represent a new chapter in imaging-based preimplantation embryo diagnostics.

Protective effect of antioxidants on the pre-maturation aging of mouse oocytes

Pre-maturation aging of immature oocytes may adversely affect the fate of an oocyte. Oxidative stress is one of the most detrimental factors affecting oocyte developmental competence and maturation during aging. In this study, experiments were designed to examine whether supplementation of antioxidants in a culture medium could protect immature mouse oocytes from damages caused by oxidative stress. Mouse oocytes at germinal vesicle stage were prevented from meiosis resumption and cultured in a medium with or without antioxidants for 12–36 h to allow oocytes to undergo aging. After aging, oocytes were cultured for maturation. Nuclear maturation, mitochondria activity, spindle morphology and DNA integrity were examined after maturation. It was found that antioxidants had protective effects on the oocytes in terms of nuclear maturation, functional mitochondria, spindle morphology and DNA integrity. As aging time was prolonged from 12 to 36 h, the protective effect of antioxidants became more obvious. However, as compared with oocytes without aging, it was found that aging significantly inhibited nuclear maturation, impaired mitochondria function, and damaged the spindle and DNA. These results indicate that pre-maturation aging is detrimental to oocytes’ competence to undergo maturation and other cellular activities, and antioxidants can protect oocytes from damages caused by aging.

Birth after human chorionic gonadotropin-primed oocyte in vitro maturation and fertilization with testicular sperm in a normo-ovulatory patient

In this report, we present a case of in vitro maturation (IVM) with surgical retrieved testicular sperm in a normo-ovulatory female. Human chorionic gonadotropin-primed IVM, testicular biopsy for sperm retrieval and intracytoplasmic sperm injection with fresh sperm were performed. Fourteen cumulus-oocyte complexes were obtained in germinal vesicle or metaphase I stage, eight oocytes reached metaphase II, seven presumptive zygotes were obtained, and three cleavage stages embryos in day 2 were transferred producing a singleton pregnancy. A single healthy newborn was obtained. Our results suggest that IVM may be an alternative for in vitro fertilization in normo-ovulatory women even if surgical retrieval of sperm is needed. Further research is required to depict contributing factors to the success of IVM in indications different from polycystic ovaries syndrome and the role of male gamete.